[TAG] (forw) Spam Prevention by Enforcing Standards

[René Pfeiffer]

On Jun 13, 2008 at 1624 -0400, Ben Okopnik appeared and said:
> On Fri, Jun 13, 2008 at 10:01:51PM +0200, Ren? Pfeiffer wrote:
> > [...]
> > The spammers don't need the MX records, their software does (provided
> > they don't use a misconfigured MTA). Their spamming tools need to get
> > the MX record unless they don't use the fallback mentioned in RFC 2821.
> > Some do, and some anti-spam rules don't accept email from domains
> > without MX record. Either way you get less mail. :)
> 
> Perhaps I'm simply unclear on spammers' methods. Why would they use
> anything other than a standard MTA? Does, e.g., 'sendmail' instantly die
> of shame when it's used in that manner? :)

The opinion is divided on this feature of Sendmail. ;) Gathering from
the reports and articles I read most spammers move their SMTP operations
to botnets. They give money to botherders and have their infected PCs
spew out the spams. This means that at the first stage no MTA is
involved. If the bots have to send the email directly they might have to
lookup the MX record. If they use the ISP's upstream mail hub, then this
might not work, but I doubt that the software infecting the bots has a
highly complicated SMTP code (yet).

I'll have a chat with some anti-spam guys later this year, I may know
more before the Christmas spams arrive. ;)

Best,
Ren?.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
Url : http://lists.linuxgazette.net/mailman/private/tag/attachments/20080613/d0db5ecd/attachment.pgp